Re: Unquoted special characters in regexps

[Richard Stallman <rms@gnu.org>]

      You further argue that "]" is a valid regular expression
    outside a character alternative.

Strictly speaking, that is true, it is a valid regular expression.

      Hence, "[" must be a valid regular
    expression outside a character alternative too.

That doesn't follow.  Strictly speaking, "[" is not a valid regular
expression.

However, that doesn't necessarily mean the manual is wrong.
There is more than one way to understand the word "special".
At the most literal level, ] is not special; if you write it
without \\, the regexp compiler won't misunderstand it.
However, it does play a special role in the syntax of regexps,
and it is not necessarily a bad thing for users to think of it
as a special character.